Scratch And Sniff Stickers And The Gas Panic Of ’87

Ever wonder how those scratch and sniff stickers manage to pack a punch of aroma into what looks like ordinary paper? The technology behind it is deceptively clever, and has been used everywhere from children’s books to compact discs.

Most Scratch and Sniff stickers are simple nose-based novelties, though they’ve seen other uses as diagnostic tools, too. As Baltimore Gas and Electric discovered in 1987, though, these stickers can also cause a whole lot of hullabaloo. Let’s explore how this nifty technology works, and how it can go—somewhat amusingly—wrong.

The Science

3M developed the scratch and sniff technology in the 1960s. It quickly gained iconic status in the decades that followed. via eBay

At its heart, scratch and sniff technology involves the microencapsulation of tiny smellable particles, which are then impregnated into stickers or other paper products. Microscopic amounts of aromatic materiale are trapped inside gelatin or plastic capsules, and then stuck to paper. When you scratch the surface, these capsules rupture, releasing their aromatic cargo into the air. It’s an elegant feat of materials engineering, originally developed by Gale W. Matson. Working at 3M in the 1960s, he’d been intending to create a new kind of carbonless copy paper.

Scratch and Sniff stickers soon became a popular novelty in the 1970s. The catchy name was perfect—it told you everything you need to know. A children’s book named Little Bunny Follows His Nose was one of the first widespread applications. Released in 1971, it  was entirely based around the whole scratch and sniff concept. Children could read along and scratch various illustrations of peaches, roses and pine needles to see what they smelled like. The book was reprinted multiple times, remaining in publication for over three decades.

Other popular media soon followed. Pop rock band The Raspberries put a scratch and sniff sticker on their album cover in 1972. Director John Waters would go on to release his 1981 film Polyester with an accompanying “Odorama” card, which featured multiple smells for viewers to sniff during the movie. The concept still resurfaces occasionally, though the gimmick is now well-worn. In 2010, Katy Perry’s Teenage Dream album smelled like cotton candy thanks to a scratch-and-sniff treatment on the Deluxe Edition, and King Gizzard & The Lizard Wizard put a similar touch on 2017’s Flying Microtonal Banana. Continue reading “Scratch And Sniff Stickers And The Gas Panic Of ’87”

A Brief History Of Calculator Watches

When humans counted on their fingers, everyone had a state-of-the-art (at the time) calculator at all times. But as we got smarter about calculation, we missed that convenience. When slide rules were king, techies were known to carry them around like swords swinging from their belts. These were replaced with electronic calculators, some also swinging from belt loops, but no matter how small they were, they still were not that handy, no pun intended. That changed around 1975. The Time Computer Calculator company produced an amazing calculator watch for Pulsar. At the time, Pulsar was a brand of the Hamilton Watch Company.

A Pulsar calculator watch (photo: The Smithsonian)

There were a few problems. First, the watch was thick. Despite its size, it had tiny keys, so you had to use a little stylus to push the keys — not as handy as you might wish. On top of that, 1975 display technology used power-hungry LEDs. So, the display was prone to turning off quickly, and the batteries died quickly.

Unsurprisingly, Hamilton, in conjunction with Electro/Data, had earlier rolled out the first LED watch in 1972. With an 18-karat gold case, it went for a cool $2,100 — a whole lot of money in 1972. The first calculator watch was also gold and went for almost $4,000. Soon, though, they brought out a stainless and a gold-filled version that came in at under $500.

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Exploring The Sounds And Sights Of Alien Worlds

The 20th century saw humankind’s first careful steps outside of the biosphere in which our species has evolved. Whereas before humans had experienced the bitter cold of high altitudes, the crushing pressures in Earth’s oceans, as well as the various soundscapes and vistas offered in Earth’s biosphere, beyond Earth’s atmosphere we encountered something completely new. Departing Earth’s gravitational embrace, the first humans who ventured into space could see the glowing biosphere superimposed against the seemingly black void of space, in which stars, planets and more would only appear when blending out the intense light from the Earth and its life-giving Sun.

Years later, the first humans to set foot on the Moon experienced again something unlike anything anyone has experienced since. Walking around on the lunar regolith in almost complete vacuum and with very low gravity compared to Earth, it was both strangely familiar and hauntingly alien. Although humans haven’t set foot on Mars yet, we have done the next best thing, with a range of robotic explorers with cameras and microphones to record the experience for us here back on Earth.

Unlike the Moon, Mars has a thin but very real atmosphere which permits the travel of soundwaves, so what does the planet sound like? Despite what fictional stories like Weir’s The Martian like to claim, reality is in fact stranger than fiction, with for example a 2024 research article by Martin Gillier et al. as published in JGR Planets finding highly variable acoustics during Mars’ seasons. How much of what we consider to be ‘normal’ is just Earth’s normal?

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Thanks For Hacking

It’s that time of year again, when the turkey roasts and we think of the important things that we’re thankful for. Here at Hackaday, we’re simply thankful for all of you out there. The readers who make Hackaday worth writing for, and the hackers out there who give us something to write about.

It’s no exaggeration to say that we have one of the most bizarrely creative communities out there, and we’re thankful to still be chronicling all of the inventive madness, all of the engineering feats, and all of the projects that succeed and those that fail. It’s truly a pleasure, day in and day out, to read and to write about.

So thank you all for being Hackaday, for sticking with us through our 20th year now, and for continuing to share your hacks and sending in the tips when you see one that you’d like us to share. Keep on hacking, and we can’t wait to see what you’re up to in 2025.

Mr Fusion powering a vehicle

Could Nuclear Be The Way To Produce Synthetic Fuel On The Cheap?

Fossil fuels can be a bit fussy to access, and geopolitics tends to make prices volatile. Burning them also takes carbon out of the ground and puts it into the atmosphere, with undesirable climate implications. The hunt for a solution has been on for quite some time.

Various synthetic fuels have been proposed as a solution, wherein carbon dioxide is captured from the air and chemically processed into useful fuel. Done properly, this could solve the climate issue where any fuel burned has its carbon later captured to make more fuel. The problem, though, is that this process is very energy intensive. Given the demands, it’s no surprise that some are looking towards nuclear reactors for the answer.

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Boss Byproducts: Corium Is Man-Made Lava

So now we’ve talked about all kinds of byproducts, including man-made (Fordite), nature-made (fulgurites), and one that’s a little of both (calthemites). Each of these is beautiful in its own way, but I’m not sure about the beauty and merit of corium — that which is created in a nuclear reactor core during a meltdown.

A necklace made to look like corium.
A necklace made to look like corium. Image via OSS-OSS

Corium has the consistency of lava and is made up of many things, including nuclear fuel, the products of fission, control rods, any structural parts of the reactor that were affected, and products of those parts’ reaction with the surrounding air, water, and steam.

If the reactor vessel itself is breached, corium can include molten concrete from the floor underneath. That said, if corium is hot enough, it can melt any concrete it comes in contact with.

So, I had to ask, is there corium jewelry? Not quite. Corium is dangerous and hard to come by. But that doesn’t stop artisans from imitating the substance with other materials.

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Linux Fu: Audio Network Pipes

Life was simpler when everything your computer did was text-based. It is easy enough to shove data into one end of a pipe and take it out of the other. Sure, if the pipe extends across the network, you might have to call it a socket and take some special care. But how do you pipe all the data we care about these days? In particular, I found I wanted to transport audio from the output of one program to the input of another. Like most things in Linux, there are many ways you can get this done and — like most things in Linux — only some of those ways will work depending on your setup.

Why?

There are many reasons you might want to take an audio output and process it through a program that expects audio input. In my case, it was ham radio software. I’ve been working on making it possible to operate my station remotely. If all you want to do is talk, it is easy to find software that will connect you over the network.

However, if you want to do digital modes like PSK31, RTTY, or FT8, you may have a problem. The software to handle those modes all expect audio from a soundcard. They also want to send audio to a soundcard. But, in this case, the data is coming from a program.

Of course, one answer is to remote desktop into the computer directly connected to the radio. However, most remote desktop solutions aren’t made for high-fidelity and low-latency audio. Plus, it is nice to have apps running directly on your computer.

I’ll talk about how I’ve remoted my station in a future post, but for right now, just assume we want to get a program’s audio output into another program’s audio input. Continue reading “Linux Fu: Audio Network Pipes”